Hello

I noticed a few weeks ago that my car use some coolant from the reservoir...when the car is cold I filled up to the full mark..after some hard driving the coolant in the reservoir goes a lil bit higher and when It cools down it comes down..But I have noticed that It's missing some since the coolant now is way below the full mark..?bad radiator cap???

No bubles
No Milky oil
No smoke
No overheat even beating the h... out of it on hot weather with A/C

what could be the problem? thanks

 

i really dont think you have a problem... if you pop the radiator cap, and its full, sounds like everything is just fine to me... now if its low when you open it, you may have a small leak somewhere...

 

Sounds like that radiator cap. I have the same problem and I have pressure tested my coolant system and everything was fine. So the only thing left is the radiator cap. Make sure you dont have it tightened all the way down because it needs to vent that is also another problem.

 

The Radiator cap is a service item. I had a pressure cap tester for so many years I wore it out. Anyway, the caps on average are good for about 30,000 miles which means the radiator caps on most cars are shot. So, it is a good habit to replace the cap when changing coolant.

A cap that is allowing vapor to escape will cause the coolant level to go down but only slowly.

 

Your problem might not even be a problem. I would check for leaks first.

 

thanks for the inputs...No leaks whatsoever coolant on the rad always full...No dripping or anthing no signs of leaks..

Can I use a 1.1 Bar Cap?

 

1.1 bar is incorrect usage of the term. 1 bar is approximately atmospheric pressure so 1.1 bar would be almost no pressure - the pressure in a flat tire. 1.1 barg (meaning 1.1 x close to atmospheric pressure) would be 15.9 psi which is the correct pressure cap for the Evo.

 

!?I found a NIB rad cap here in my house that fits the evo and it says 1.1 and the evo one says 0.9..